4TPV

Crystal Structure of Hookworm Platelet Inhibitor


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 0.194 
  • R-Value Work: 0.150 
  • R-Value Observed: 0.152 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

The structure of hookworm platelet inhibitor (HPI), a CAP superfamily member from Ancylostoma caninum.

Ma, D.Francischetti, I.M.Ribeiro, J.M.Andersen, J.F.

(2015) Acta Crystallogr F Struct Biol Commun 71: 643-649

  • DOI: https://doi.org/10.1107/S2053230X1500271X
  • Primary Citation of Related Structures:  
    4TPV

  • PubMed Abstract: 

    Secreted protein components of hookworm species include a number of representatives of the cysteine-rich/antigen 5/pathogenesis-related 1 (CAP) protein family known as Ancylostoma-secreted proteins (ASPs). Some of these have been considered as candidate antigens for the development of vaccines against hookworms. The functions of most CAP superfamily members are poorly understood, but one form, the hookworm platelet inhibitor (HPI), has been isolated as a putative antagonist of the platelet integrins αIIbβ3 and α2β1. Here, the crystal structure of HPI is described and its structural features are examined in relation to its possible function. The HPI structure is similar to those of other ASPs and shows incomplete conservation of the sequence motifs CAP1 and CAP2 that are considered to be diagnostic of CAP superfamily members. The asymmetric unit of the HPI crystal contains a dimer with an extensive interaction interface, but chromatographic measurements indicate that it is primarily monomeric in solution. In the dimeric structure, the putative active-site cleft areas from both monomers are united into a single negatively charged depression. A potential Lys-Gly-Asp disintegrin-like motif was identified in the sequence of HPI, but is not positioned at the apex of a tight turn, making it unlikely that it interacts with the integrin. Recombinant HPI produced in Escherichia coli was found not to inhibit the adhesion of human platelets to collagen or fibrinogen, despite having a native structure as shown by X-ray diffraction. This result corroborates previous analyses of recombinant HPI and suggests that it might require post-translational modification or have a different biological function.


  • Organizational Affiliation

    Laboratory of Malaria and Vector Research, NIH/NIAID, 12735 Twinbrook Parkway, Rockville, MD 20852, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Platelet inhibitor
A, B
182Ancylostoma caninumMutation(s): 0 
Gene Names: HPI
UniProt
Find proteins for Q962V9 (Ancylostoma caninum)
Explore Q962V9 
Go to UniProtKB:  Q962V9
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ962V9
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
GOL
Query on GOL

Download Ideal Coordinates CCD File 
C [auth A]GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 0.194 
  • R-Value Work: 0.150 
  • R-Value Observed: 0.152 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 39.158α = 90
b = 51.985β = 90.05
c = 73.94γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2015-04-22
    Type: Initial release
  • Version 1.1: 2015-06-10
    Changes: Database references
  • Version 1.2: 2015-06-24
    Changes: Database references
  • Version 1.3: 2023-12-27
    Changes: Advisory, Data collection, Database references, Derived calculations, Other, Refinement description, Source and taxonomy, Structure summary